Rope clamp

ABSTRACT

The specification describes a rope clamp with at least one clamping body, which can be moved between wedge-shaped guiding faces. A rear part of the clamping body remote from the rope is constructed as a pivoting edge or is rounded and on actuation of the clamp the clamping body slides into its clamping position with the rear part on an associated guiding face comes into engagement with the rope. Following this the clamping body swings about the pivoting edge as a pivot axis until the whole clamping face lies against the rope. The clamping face is so arranged that in the clamping position the front edge of the clamping face lies behind, in terms of the pulling direction, a line drawn perpendicular to the direction of pulling through the axis of rotation or at the most lies on this axis. Furthermore for actuating the clamp to release it the clamping body is first swung about its axis of rotation formed by its pivot edge before it begins its sliding movement on the guiding face.

United States Patent [191 Pasbrig ROPE CLAMP [76] Inventor: Max Pasbrig,Casa Luce-Via all- Eco, Orselina, Switzerland 22 Filed: Jan. 15,1971

21 Appl.No.: 106,664

[30] Foreign Application Priority Data Jan. 19, 1970 Germany ..P 20 02184.5

[52] US. CL ..24/l26, 24/132 R [51] Int. Cl... ..Fl6g 11/04 [58] Fieldof Search...22l/230 AT, 134 KD, 230 A 126, 24/136, 263 B, 249 PP, 249HL, 249 R 263 DL, 263 P, 249 DP, 134 W, 134 CP 134 N, 251,132 WL, 132 R;279/37, 57,107,

[5 6] References Cited UNITED STATES PATENTS 1,710,273 4/1929 Sebring..24/1 34 KD 3,294,444 12/1966 Anderson... ..24/230 AT 32,210 4/1861Soule ..24/l26 R 589,224 8/1897 Samuelson ..24/126 1,634,422 7/1927Holmes ..279/107 1 1] 3,718,951 [451 March 6, 1973 3,413,692 12/ 1968Pressley ..24/230 AM Pnmary ExaminerBernard A. Gelak Attorney-Curtis,Morris & Safford [5 7 ABSTRACT The specification describes a rope clampwith at least one clamping body, which can be moved between wedge-shapedguiding faces. A rear part of the clamping body remote from the rope isconstructed as a pivoting edge or is rounded and on actuation of theclamp the clamping body slides into its clamping position with the rearpart on an associated guiding face comes ifitoengagement with the rope.Following this the clamping body swings about the pivoting edge as apivot axis until the whole clamping face lies against the rope.

The clamping face is so arranged that in the clamping A position thefront edge of the clamping face lies behind, in terms of the pullingdirection, a line drawn perpendicular to the direction of pullingthrough the axis of rotation or at the most lies on this axis.Furthermore for actuating the clamp to release it the clamping body isfirst swung about its axis of rotation formed by its pivot edge beforeit begins its sliding movement on the guiding face.

7 Claims, 4 Drawing Figures 3 1 a "J t PATENTEDMAR 6 ma SHEET 10F 3Fig.1

INVEN'I'UR: MAX PALE/HG BYI BACKGROUND OF INVENTION 1. Field to WhichInvention Relates The present invention relates to rope clamps and moreparticularly to rope clamps comprising a clamping part which can bemoved between wedge-shaped guide faces. In the present specification andclaims the expression rope is to be taken to cover cables, cords andother like materials.

2. The Prior Art In accordance with one prior proposal a slackeningclamp for overhead lines or ropes was to comprise a clamp body with alateral longitudinal opening. In the interior space of the clamp bodytwo clamping jaws, wedge-shaped externally, were provided opposite eachother so as to be capable of sliding. The ends with the lesser wedgeheight of the gripping or clamping jaws were connected respectively withends of equally long limbs of an opening spring made of spring wire. Thecross part of the spring was arranged so as to be perpendicular to thespring plane. The spring length between the transverse part of thespring and the clamping jaw is so selected that when the opening springis inserted into the clamping body the insertion of the line or rope ispossible both into the longitudinal opening of the clamping body andalso from the direction of the end faces of the clamping jaws. However,no means are provided for bringing about release of the clamping action,something which constitutes a disadvantage in many applications. Inparticular it is a disadvantage that the rope must be completely freedof tension for releasing the clamping action. Similar disadvantages arealso present in a connecting sleeve for overhead lines in which a doubleconical sleeve is provided with clamping" jaws arranged in it. Also aknown rope clamp with a wedge mounted in it has substantially the samedisadvantages.

. In accordance with a further prior proposal a device for thereleasable clamping of at least one line or rope or the like was to beprovided with a housing which has at least one internal hole acceptingat least one springloaded axially displaceable clamping body whichclamps the inserted rope with an automatic locking action. The hole wasto be associated with at least one further hole running obliquely inrelation to it and which forms a chamber with it in which the clampingbody was to be arranged and connected in a pivoting manner with thespring associated with it. For releasing the clamping action and forwithdrawing the clamping body an externally accessible actuating elementwas to be provided on whose actuation the clamping body was firstlymoved out of its clamping position in the axial direction of the holeswith a pivoting action and, when this had been done, was to bewithdrawn. As a result the force, necessary for releasing the clampingaction and applied to'the actuating element, was reduced so that theabove-mentioned disadvantages could be substantially avoided. It would,however, be desirable to provide for a still further reduction of theforce applied to the actuating sleeve, which is necessary for releasingthe self-locking clamping action. This applies more particularly forcable clamps used for clamping cables or the like which are subjected tohigh tension stresses, since the force required for release alsoincreases with the magnitude of the tension in the cable.

SUMMARY OF INVENTION On the basis of the above considerations it istherefore one aim of the invention to provide an improved rope clamp inwhich the force for releasing the selflocking clamping action is as lowas possible and the release of the self-locking action can take placeeven with extremely high tension forces without previously releasing thetension in the rope. This aim is achieved in that the clamping partforming a clamping body is provided on its rear part remote from therope with a pivoting edge or is rounded, and in this respect moreparticularly the extended end of the clamping part is guided by means ofa transverse pin in a longitudinally moving part, more particularlyusing a slot guide, so that the clamping part is swung positively aftersliding on its conical guide face about its pivot edge and finally thefront edge of the clamping face lies behind, in terms of the directionof pull, a line perpendicular to the direction of pull and passingthrough the pivot axis, or at the most lies on this line.

A rope clamp in accordance with the invention possesses moreparticularly the advantage that even in the case of high rope tensionsthe rope does not have to be slackened off before the rope tension canbe released, since with the rope clamp in accordance with the inventionthe force required for release is not proportional to the tension forcein the clamp, as is the case with the previously proposed rope clamps,but in accordance with the invention the release force, which ismoreover very small, is practically independent from the tension forceacting on the rope. The automatic locking action can therefore bereleased by hand, even if the rope is subjected to a tension load ofseveral tons. Furthermore there is the advantage that on releasing theclamping action any damage to the rope is avoided.

The advantages obtained with the invention are due to the fact that twopossibilities of movements are provided for the clamping part formingone clamping body. In accordance with the invention a rotary or rockingmovement is coupled with a longitudinal movement in such a manner thatthe clamping body located in its withdrawn position firstly carries out,after the insertion of the rope, a longitudinal movement, until it comesinto engagement with the rope, following which it then carries out apivoting or rocking movement until its clamping face lies fully againstthe rope. If the rope is subjected to a very large tension force, theclamping body then carries out a further longitudinal movement whichleads to a self-locking action which becomes stronger and stronger. Forrelease the clamping body is first swung or rocked, something which ispossible, in the case of a suitable construction and arrangement, evenwhen the rope is under a high tension load. Owing to the rocking ortilting movement, however, the friction force between the clamping forceof the clamping body and the rope is substantially decreased so that theclamping body can now begin to perform its longitudinal movement intothe release position.

In accordance with a preferred embodiment of the invention thelongitudinal moving part is an actuating sleeve which is subjected tospring loading.

In accordance with a still further preferred feature of the inventionbetween the actuating sleeve and the gripping part there is a furtherspring element which tends to twist the clamping part into its positionswung away from the rope. In the case of this embodiment two springs arethus required, of which one is connected with movement of the clampingpart in the longitudinal direction of the rope and the other with therotary movement of the clamping part.

In this respect it is, however, significant that the spring concernedwith the movement in the longitudinal direction tends to move theclamping part into engagement with the rope, while the other springswings the clamping part into the release position. Since thefirst-mentioned spring is substantially stronger in construction thereis the consequence of this arrangement that the clamping part is movedtowards the rope in its swung away position and its back part reachesthe furthest forward position, that is to say the furthest forwardposition in the direction of tension of the rope. When this position isreached it is swung on the one hand by the pressure of the firstmentioned spring and by a pulling force acting on the rope against thedirection of action of the second spring. The cooperation specified ofthe springs is convenient, since in this manner the rope clamp functionsparticularly well and more particularly the clamping parts are held awayfrom the rope during their release movement. It is also possible toprovide a still further spring which presses the clamping part with itsback part against the associated guide face. This function can, however,be taken over by the spring bringing about the rotary movement of theclamping part.

In accordance with a further preferred embodiment of the invention twoor more gripping parts engage opposite parts of the rope in a previouslyproposed manner and the guide faces associated with gripping partsrun ina wedge shaped manner towards each other in the direction of pull on therope. This embodiment offers a still higher degree of reliability.Furthermore it is possible with one and the same rope clamp to clampropes which have very different diameters.

It is convenient when the slots of the slot guide means run obliquely orin a curved manner in relation to the direction of pull. It isadvantageous if the housing is box-shaped and the actuating sleeve ismade up of a ring of rectangular cross-section. Furthermore on the frontand rear narrow surfaces of the housing inlet and outlet openings forthe rope can be provided. Furthermore on the narrow longitudinalsurfaces of the housing recesses can be provided in which helicalsprings are accommodated.

LIST OF SEVERAL VIEWS OF DRAWINGS The invention will now be described inmore detail with reference to the accompanying drawings and thefollowing description of embodiments.

FIG. 1 is a diagrammatic view for explaining the gripping principleforming the basis of the invention.

FIG. 2 is a section of a first embodiment of the invention.

FIG. 3 is a view, partly in phantom, of a second embodiment of theinvention.

FIG. 4 shows an actuating sleeve suitable for use in the embodiment ofFIG. 3.

DESCRIPTION OF PREFERRED EMBODIMENTS An elongated clamping or grippingbody 1 is provided with an elongated gripping face 2 for frictionalclamping of a rope 3. At its inner end 4 the clamping body 1 is roundedor constructed as a fulcrum. Its back part 4 lies against a guide faceor inner end 5 which runs in a wedge-shaped or conical manner.

The gripping or clamping body 1 has a shank 6, whose end is guided in acam slot 7 of an actuating sleeve or slide member 8. The actuatingsleeve 8 is loaded by an associated spring 9.

When the actuating sleeve 8 is withdrawn, the shank 6 of the gripping orclamping body 1 moves in the slot 7. It can be supported in thismovement by a further spring 10. When the front or leading edge A of thegripping or clamping face 2 lies behind, in terms of the tensiondirection denoted by the arrow 11, the rounded abutment B of the innerend 4 of the clamping body 1 or in a vertical line in relation to thedirection of tension, or possibly somewhat in front of it, the rockingor pivoting movement of the clamping body 1 occurs without anysubstantial application of force. It is correspondingly also possible torelease ropes under tension from the clamping action.

On further movement backwards of the actuating sleeve 8 the clampingbody 1 will then begin its sliding movement on the guiding face 5, sothat it comes further and further away from the rope 3.

In the case of the embodiment of the invention shown in FIG. 2 a rope 3runs on the front end 13 of a substantially round and sleeve-shapedclamping member. On the inner end there is a conically shaped guide faceor inner cam surfaces 14 for two elongated clamping members 1, which inaccordance with the principle shown in FIG. 1 are guided in slots 7 ofan actuating sleeve or slide member 8. A shackle spring 12 urges theclamping body 1 into their position swung away from the rope and at thesame time ensures that the clamping members 1 are held abutting againsttheir associated abutting cam surfaces 14 when the actuating sleeve 8 ispressed back against the action of the spring 9 associated with it.

In the case of the embodiment of the invention shown in FIG. 3 thehousing of the rope clamp is constructed in the form of a box. Theguidance of the clamping bodies 1 is ensured by means of cam slots 7which are provided in an U-shaped slide 16. Two helical springs 17 actupon the slide 16. The springs 17 are placed from below and from abovein corresponding recesses 18 in the housing. The actuation of the U-shaped slide 16 is carried out by means of handles or lugs 19, oralternatively by means of an actuating sleeve 20 as shown in FIG. 4.

As is shown more especially in FIG. 1, the abutment surface 2 of thegripping or clamping body 1 is grooved or otherwise roughened. Thisincreases the friction occurring, as may be very convenient, moreespecially in the case of very smooth ropes.

In the case of the embodiment of the invention shown in FIG. 3, in whichthe housing of the rope clamp is constructed in the form of a box, alateral slot 15 is provided which makes possible insertion of the rope 3from the side. There is therefore with this embodiment of the inventionthe advantage that the rope does not have to be threaded through thelength of the housing from the front and can instead be easily placed infrom the side. The actuating sleeve 20 shown in FIG. 4, which can beused for actuating the U-shaped slide 16 in the embodiment of theinvention in accordance withFlG. 3, is also provided with a lateral slot21 so that the lateral insertion of the rope 3 is not obstructed.

It is significant that the clamping body is positively rocked or swungafter completion of its sliding movement about its fulcrum when theactuating sleeve moves further forwards owing to its spring loading,preferably in the direction of pull on the rope.

Even although guidance by means of slots for achieving a connection ofthe clamping bodies or the clamping part with a longitudinally movingpart constructed more particularly as an actuating sleeve is moreparticularly preferred, it is, however, possible, as can be readilyseen, also to provide any other type of guiding means which provide forthe two possibilities of movement, in accordance with the invention, ofthe clamping or gripping part.

Preferably all parts can be made of plastics material, more particularlyincluding the springs, in order to ensure a high degree of resistance tocorrosion.

It will be noted that in the embodiments of the invention and anglebetween the gripping face of the clamping part and a line between thefront edge of the clamping face and the pivot point against the guidesurface makes an angle of at least 90, that is to say inmost casessomewhat more than 90.

What I claim is:

l. A releasable clamp comprising a. an elongated housing having alongitudinal axis, an inner end and an outer end, said inner end havingan inner cam surface converging with the longitudinal axis toward theinner extremity thereof,

b. a slide member longitudinally movable relative to said housing andhaving a cam slot diverging from said longitudinal axis toward the innerend of the housing,

c. an elongated clamping member within said housing having an inner endand an outer end, the inner end having an elongated gripping surfacewith a leading edge at the inner end thereof at one side adjacent saidlongitudinal axis and a rounded abutment on the other side for slideableand rocking engagement with said inner cam guide surface, the outer endof said clamping :member comprising a shank portion and a cam followerengageable with the cam slot, and

d. spring means biased to slide the slide member toward the inner endfor longitudinal movement of the clamping member from a release positiontoward the inner end until the converging cam guide surface brings theleading edge of the gripping surface into engagement with the object tobe clamped and thereafter to lock the clamping member by rocking saidmember about the point of contact of said abutment with said cam surfaceby the camming action of the cam slot until the remainder of thegripping surface firmly engages the object to be clamped.

2. A clamp as defined in claim 1 wherein the longitudinally movableslide member is actuated and controlled by a sleeve member at leastpartly surrounding and slideable on the housing.

3. A clamp as defined in claim 1 wherein the cam follower on the shankof the clamping member is a transverse in.

4. clamp as defined in claim ll wherein the housing has a longitudinalslot in one side and along the length thereof for lateral insertion ofthe object to be clamped.

5. A clamp as defined in claim 1 wherein the housing has a longitudinalslot in one side and along the length thereof for lateral insertion ofthe object to be clamped and the slide member is actuated and controlledby a sleeve member slideable on the housing and having a correspondinglongitudinal slot.

6. A clamp as defined in claim 1 having two opposed elongated clampingmembers actuated by opposed converging cam slots, cam surfaces and camfollowers.

7. A clamp as defined in claim 6 wherein the opposed clamping membersare additionally spring-biased against the opposed guide surfaces.

1. A releasable clamp comprising a. an elongated housing having alongitudinal axis, an inner end and an outer end, said inner end havingan inner cam surface converging with the longitudinal axis toward theinner extremity thereof, b. a slide member longitudinally movablerelative to said housing and having a cam slot diverging from saidlongitudinal axis toward the inner end of the housing, c. an elongatedclamping member within said housing having an inner end and an outerend, the inner end having an elongated gripping surface with a leadingedge at the inner end thereof at one side adjacent said longitudinalaxis and a rounded abutment on the other side for slideable and rockingengagement with said inner cam guide surface, the outer end of saidclamping member comprising a shank portion and a cam follower engageablewith the cam slot, and d. spring means biased to slide the slide membertoward the inner end for longitudinal movement of the clamping memberfrom a release position toward the inner end until the converging camguide surface brings the leading edge of the gripping surface intoengagement with the object to be clamped and thereafter to lock theclamping member by rocking said member about the point of contact ofsaid abutment with said cam surface by the camming action of the camslot until the remainder of the gripping surface firmly engages theobject to be clamped.
 1. A releasable clamp comprising a. an elongatedhousing having a longitudinal axis, an inner end and an outer end, saidinner end having an inner cam surface converging with the longitudinalaxis toward the inner extremity thereof, b. a slide memberlongitudinally movable relative to said housing and having a cam slotdiverging from said longitudinal axis toward the inner end of thehousing, c. an elongated clamping member within said housing having aninner end and an outer end, the inner end having an elongated grippingsurface with a leading edge at the inner end thereof at one sideadjacent said longitudinal axis and a rounded abutment on the other sidefor slideable and rocking engagement with said inner cam guide surface,the outer end of said clamping member comprising a shank portion and acam follower engageable with the cam slot, and d. spring means biased toslide the slide member toward the inner end for longitudinal movement ofthe clamping member from a release position toward the inner end untilthe converging cam guide surface brings the leading edge of the grippingsurface into engagement with the object to be clamped and thereafter tolock the clamping member by rocking said member about the point ofcontact of said abutment with said cam surface by the camming action ofthe cam slot until the remainder of the gripping surface firmly engagesthe object to be clamped.
 2. A clamp as defined in claim 1 wherein thelongitudinally movable slide member is actuated and controlled by asleeve member at least partly surrounding and slideable on the housing.3. A clamp as defined in claim 1 wherein the cam follower on the shankof the clamping member is a transverse pin.
 4. A clamp as defined inclaim 1 wherein the housing has a longitudinal slot in one side andalong the length thereof for lateral insertion of the object to beclamped.
 5. A clamp as defined in claim 1 wherein the housing has alongitudinal slot in one side and along the length thereof for lateralinsertion of the object to be clamped and the slide member is actuatedand controlled by a sleeve member slideable on the housing and having acorresponding longitudinal slot.
 6. A clamp as defined in claim 1 havingtwo opposed elongated clamping members actuated by opposed convergingcam slots, cam surfaces and cam followers.